Easily openable carton top



Sept. 3@, 1958 w. H. HEINE EASILY OPENABLE CARTON TOP Filed April 30, 1956 United States Patent (3 EASILY OPENABLE CARTON TOP William H. Heine, Battle Creek, Mich., assignor to Kellogg Company, Battle Creek, Miclr, a corporation of Delaware Application April 30, 1956, Serial No. 581,659

1 Claim. (Cl. 229-51) This invention relates to improvements in an easy opening carton and refers particularly to a carton of the usual cardboard type having a top construction so contrived as to permit the easy and convenient opening thereof.

Cartons and cardboard boxes of the type used in the sale of merchandise, such as, cereal breakfast food, soap powder and the like have heretofore been provided with various expendients for opening or removing the top thereof to gain access to the contents thereof. However, in most cases the expedients have either been complicated and expensive or ineffective for their intended purpose.

The provision and use of scored or perforated lines upon a carton top has heretofore been resorted to but in most instances the carton top construction is such that it is diificult to rupture the scored or perforated line.

The present invention contemplates use of a scored or perforated line upon a carton top which is adapted to be ruptured to gain access to the contained material. However, as an important feature of the invention the scored or perforated line is so disposed adjacent other portions of the carton top as to facilitate the rupturing of the line.

The detailed construction and advantages and features of the present invention will be apparent from the accompanying drawing and following description.

In the drawing,

Fig. 1 is a perspective view of a carton having a top embodying the features of the present invention.

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1.

Fig. 3 is a perspective view similar to Fig. 1 illustrating the manner in which the perforated line is progres sively ruptured from the center of the carton top to the ends thereof.

Referring in detail to the drawing, 1 indicates a cardboard carton of the type generally used for containing cereal breakfast food, soap powder, soap flakes or the like. The carton 1 comprises a front side wall 2, a rear side wall 3, opposite end walls 4 and 5 and a bottom (not shown). The front side wall 2 terminates in an upper top flap 6 and the rear side wall terminates in a similar lower top flap 7. The end Walls 4 and 5 terminate in upper end flaps 8, only one of which is shown.

In closing the box or carton top, the end flaps are turned inwardly toward each other and the upper and lower top flaps 6 and 7 are disposed in overlapping relationship to each other, each of the flaps 6 and 7 being of a Width less than the total width of the carton. The

Patented Sept. 30, 1958 overlapped portions of the flaps 6 and 7 are adhesively secured together along their common area of overlap and, if desired, the flaps 6 and 7 may be adhesively secured to the tops of the end flaps 8. However, the lastmentioned adhesive securement is not essential and may in some instances not be desirable. The end flaps 8 are preferably relatively short and underlie a minor portion of the area of the flaps 6 and 7.

There are essentially three very important features of the present invention: (1) the flap 6 is provided with a perforated line 9 which extends the entire length of the top, (2) the perforated line 9 lies substantially coincident and above the edge 10 of the lower top flap 7, and (3) the perforated line lies in the upper overlapping flap, that is, the flap 6, as shown in the drawing.

It will be noted that where flap 6 overlaps flap 7 a double thickness of material is provided, that is, the area designated by the numeral 11. Being of double thickness the material of the top at the area 11 is stifier than the remaining single thickness of the top and, hence, resists bending or deflection, when a force normal to the top is applied, to a greater degree than does the single thickness portion of the top. In addition, the area 11 carries adhesive between the overlapping flaps which further stiffens said area.

It will also be noted that the perforated line 9 is provided in a single thickness portion of the top and is provided in substantial registration with a lateral defining edge of the area 11. Hence, when a normal force is applied to the top as by the finger 12, shown in phantom in Fig. 3, the area 11 resists deflection to a greater degree than does the area of single thickness, indicated by reference numeral 13 in Fig. 3. Therefore, a shearing stress is exerted upon the line of demarcation between the areas 11 and 13, that is, along the perforated line 9. The lateral edge of the area 11 at the perforated line 9 exerts a reacting force against which the single thickness material may be torn, said edge functioning as a straight edge along which paper is conventionally torn.

If the normal pressure, exerted by the finger 12 is concentrated at the longitudinal center of the area 13, the tearing is initiated at the longitudinal center of the perforated line 9 and proceeds progressively toward both ends of said line as the normal pressure is continued. With the rupturing of the line 9 access to the contents may easily be gained since the top is thus severed in two.

In addition, it will be noted that the perforated line 9 is provided in the upper top flap 6 which is preferable since, if it were provided in the lower top flap 7, normal pressure on the single thickness portion of the top would tend to delarninate the area 11 and impair the effectiveness of said area as a non-deflective straight edge.

Modifications of the present invention which do not depart from the spirit of the invention may suggest themselves to those skilled in the art and, hence, I do not wish to be limited to the exact details shown and described except as necessitated by the appended claim.

I claim as my invention:

A cardboard carton comprising opposite side walls, opposite end walls, a bottom, and a top, said top comprising an upper single thickness relatively defiectible top flap joined to one side wall, a lower single thickness relatively deflectible top flap joined to the other side single thickness portion of the upper top flap suhstantial' alignment above the underlying loiigitudihail terminal edge of the lower top flap, whereby a force exerted normal to the single thickness upper flap portion of the top exerts at substantially the center of the line of perforation a shearing stress which acts along said line outwardly in both directions from said center.

References Cited in the file of this patent UNITED STATES PATENTS 1,105,144 Johnson July 28, 1914 2,543,084 Williamson t a1. Feb. 27, 1951 2,626,096 Hickin Jan. 20, 1953 2,778,562 Tilly Jan. 27, 1957 

